Jonathan Taee Posted February 19, 2008 Share Posted February 19, 2008 I have a Photec IV high speed 16mm camera and want to shoot at 2000fps. I don't have a light meter that can measure the light needed for that frame rate. How should I go about measuring the light for such a high frame rate? Jonathan Taee Link to comment Share on other sites More sharing options...
Site Sponsor Robert Houllahan Posted February 19, 2008 Site Sponsor Share Posted February 19, 2008 I have a Photec IV high speed 16mm camera and want to shoot at 2000fps. I don't have a light meter that can measure the light needed for that frame rate. How should I go about measuring the light for such a high frame rate? Jonathan Taee Is this a rotary prism camera? like a hycam? you need to find the shutter i.e. a 180 degree shutter will be 1/4000th of a second and the minimum optical stop, i.e. my HycamII's are a minimum of t4 then you need to find the exposure for the stock you are using how many foot-candles needed for the time and film ISO An example we recently did a 500fps shot on a 4 sq foot area with a Locam and a pair of 2K tungsten lights which measured at 1800fc and I had a load of Tri-x that I rated at 140iso as I cross processed as negative. I exposed at a 2.8/4 split and the shot came out great. On another setup there were 450 1k lowels and 500t at 8000fps exposed at a t4 I think there was around 4000fc on the subject. The key with any hi speed photography is dump as much light as you can afford onto just the area you are trying to photograph, open face tungstens work best so 4 or 5 or 6 or 400 :blink: lowell 1K totas or omnis as close as you can get them to the subject. -Rob- Link to comment Share on other sites More sharing options...
Nick Mulder Posted February 19, 2008 Share Posted February 19, 2008 How should I go about measuring the light for such a high frame rate? extrapolate Link to comment Share on other sites More sharing options...
Site Sponsor Robert Houllahan Posted February 19, 2008 Site Sponsor Share Posted February 19, 2008 extrapolate You could use a regular sekonic L398 with the high slide..... -Rob- Link to comment Share on other sites More sharing options...
Premium Member David Auner aac Posted February 19, 2008 Premium Member Share Posted February 19, 2008 On another setup there were 450 1k lowels and 500t at 8000fps exposed at a t4 I think there was around 4000fc on the subject. Hi Rob, am I reading this correctly? 450 as in four hundred and fifty Lowel 1ks? Why not use a smaller number of 5ks or even bigger tungstens? Cheers, Dave Link to comment Share on other sites More sharing options...
Site Sponsor Robert Houllahan Posted February 19, 2008 Site Sponsor Share Posted February 19, 2008 Hi Rob, am I reading this correctly? 450 as in four hundred and fifty Lowel 1ks? Why not use a smaller number of 5ks or even bigger tungstens? Cheers, Dave Heh heh... can't say exactly but the 1k's were cheap in case they broke, they are easy to place around a large object and most 5k's are fresnels which don't work as well as open face reflectors...all other lights were tested... -Rob- Link to comment Share on other sites More sharing options...
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